In general, the present disclosure relates to a nucleic-acid extraction method and a nucleic-acid extraction cartridge. More particularly, the present disclosure relates to a method for extracting a nucleic acid from a sample by carrying out an ultrasonic process on the sample, a process of adsorbing foreign substances and the like from the sample and an electrophoresis process on the nucleic acid in the same channel and relates to a nucleic-acid extraction cartridge adopting the method.
Nucleic-acid amplification reaction methods such as a PCR (Polymerase Chain Reaction) method and a LAMP (Loop-Mediated Isothermal Amplification) method are applied to a variety of fields in the biotechnology. For example, diagnoses based on DNA and/or RNA base sequences are carried out in the medical field whereas DNA appraisements such identifications of genetically-engineered plants are put to practical use in the agricultural field.
In a nucleic-acid amplification reaction, a nucleic acid in a sample having a very small quantity is amplified with a high degree of efficiency in order to allow the acid to be detected. If the quantity of the nucleic acid contained in the sample is extremely small, however, the quantity may be smaller than a detection lower limit in some cases. In addition, if the concentration of the nucleic acid contained in the sample is very low, the acid may not be detected in some cases because the sample having a volume introducible into a reaction field does not contain an enough nucleic acid to be amplified. Problems raised in such cases can be solved by adoption of an effective method described as follows. The nucleic acid is refined, condensed and extracted in advance before being introduced into a reaction field.
As is generally known, methods in the past for extracting a nucleic acid include a method making use of phenol, chloroform or ethanol, a method making use of a column or a filter and a method making use of magnetic silica beads. The column and the filter are used for adsorbing the nucleic acid.
For example, Japanese Patent Laid-open No. 2005-080555 discloses a method for condensing a nucleic acid by making use of a porous carrier capable of adsorbing the nucleic acid. In addition, a method for condensing a nucleic acid in a capillary electrophoresis phenomenon is disclosed in “On-line sample preconcentration in capillary electrophoresis: Fundamentals and applications.” Journal of Chromatography A., Vol. 1184 (2008) pp. 504-541.